The Role of Blood Cell Composition in Epidemiologic Studies of Telomeres

Cellular aging and telomere dynamics in pregnancy

PURPOSE OF REVIEW

Telomere biology is an emerging area of scientific interest. Telomeres are deoxynucleic acid caps at the ends of chromosomes that naturally shorten over one's lifespan; because of this, short telomeres have been studied as a marker of cellular aging. Given the association between short telomeres and genetic and environmental factors, their role in pregnancy has become an intriguing area of research.

RECENT FINDINGS

This review describes recent data on telomeres in pregnancy. Specifically, we discuss the association between short maternal leukocyte telomeres and poor nutritional status, between short neonatal telomeres and greater maternal psychosocial stress, and between shorter fetal amniotic membrane telomeres and the spontaneous onset of parturition. We also review recent studies suggesting that events during pregnancy can impact telomeres in the offspring years into the future.

SUMMARY

Telomere length varies in maternal, placental, and neonatal cells, but within each of these compartments telomeres may play their own distinct role during pregnancy. Whether telomeres are reflective of the cumulative impact of stressors, or part of an as-yet unknown fetal programming mechanism is an area of interest. With future research, we may work toward a better understanding of gestational biology which could have far reaching intergenerational impacts.

The associations of hostility and defensiveness with telomere length are influenced by sex and health status

Background

Shorter telomere length (TL) may indicate premature cellular aging and increased risk for disease. While there is substantial evidence for shorter TL in individuals suffering from psychiatric disorders, data is scarce on maladaptive personality traits related to coronary artery disease (CAD). The purpose of this study was to evaluate the association of TL with hostility and defensiveness in individuals with CAD or other non-cardiovascular illnesses and whether associations were moderated by CAD status and sex.

Methods

One thousand thirty-six individuals (M_age = 65.40 ± 6.73 years) with and without CAD completed the Marlowe-Crowne Social Desirability Scale and the Cook–Medley Hostility Scale. Relative TL was measured via quantitative polymerase chain reaction of total genomic DNA samples. Analyses involved hierarchical regressions on TL, performed separately for hostility and defensiveness, controlling for pertinent sociodemographic, behavioural, and medical risk factors. Separate analyses were performed on 25 healthy participants.

Results

A hostility by sex interaction emerged (β = − .08, p = .006) in the patient groups, where greater hostility was associated with shorter TL in women only (p < .01). A Defensiveness by CAD status interaction (β = − .06, p = .049) revealed longer TL in more defensive CAD patients only (p = .06). In healthy men, shorter TL was observed in those with greater defensiveness (β = .52, p = .006) but lower hostility (β = − .43, p = .049).

Conclusion

Hostility and defensiveness are differentially associated with TL as a function of sex and health status. The implication of these results for health remains to be determined, but propose an additional pathway through which the effect of maladaptive personality traits may contribute to CV and other disease.